Integrate jsdoc into Grunt and allow for JS Documentation to be generated

1. Update your Node dependencies

   npm ci

2. Run the jsdoc tool:

   grunt jsdoc

   1. Confirm that there were no errors
3. Open your site in your browser and navigate to the jsdocs (by appending /jsdoc to the site name) i.e. http://hostname/path/to/your/site/jsdoc
4. Browse the documentation
   1. Confirm that most documentation is present

Note: This issue does not seek to fix all documentation, but attempts to fix a great deal of it. More will come as we fix code.

Additional testing step for jsdoc linting

1. Run JSDoc manually:

   npx jsdoc -c .grunt/jsdoc/jsdoc.conf.js --pedantic

   1. Confirm there was no error or output
2. Edit lib/amd/src/str.js
3. Add a new line just before the @copyright line:

   /**

   * Fetch and return language strings.

   *

   * @package core

   * @module core/str

   * @copyright 2015 Damyon Wiese <damyon@moodle.com>

   * @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later

   * @since 2.9

   */

4. Run JSDoc manually:

   npx jsdoc -c .grunt/jsdoc/jsdoc.conf.js --pedantic

   1. Confirm there was an error:

      WARNING: The @package tag does not permit a value; the value will be ignored. File: str.js, line: 16

5. Check the exit code (must be the next command):

   echo $?

   1. Confirm that it was non-zero (i.e. it should be 1).